One of the key strengths of Codility lies in its ability to predict the on-the-job performance of developers. Through its extensive library of programming problems and its proprietary algorithms, Codility can accurately gauge a candidate's proficiency in various programming languages, data structures, and algorithms. This predictive capability is invaluable for companies seeking to hire top talent who can quickly adapt to the demands of the job and contribute meaningfully to the team.

The fact of being web based helps a lot, so that the candidates don't need to install any software nor the interviewer. The code highlighting for code interview and the graphical tool for system design interviews are also very good. There is no delay on the interactions.

What I like best about Codility is its ability to provide objective and accurate programming assessments. The platform offers a wide range of challenges that cover various areas of computer science, from algorithms to data structures. The automated and detailed evaluations help identify candidates' strengths and areas for improvement efficiently. Additionally, the interface is intuitive and easy to use for both recruiters and candidates. The detailed reporting feature is also very useful for post-assessment analysis.